Hello,
When I save a project with 8 stereo tracks at around 9 min long the date folder is 200MB.
When do Tracks> Stereo track to mono for all the tracks and save the project, the data folder is 731MB.
I thought the mono tracks would actually produce a smaller data folder, but instead much larger.
Just curious why that is.
Thanks for any ideas.
frew
You’ve not given enough detail.
Have you taken into account dependencies (http://manual.audacityteam.org/man/audacity_projects.html#dependencies) and UNDO history?
Do the tracks have the same sample rate and sample format?
The UNDO history is cleared when the project is closed or removed via the “View > History” window (http://manual.audacityteam.org/man/view_menu.html#history).
More detailed answer, given I had already written it before seeing Steve’s reply.
By default that should take about 1.4 GB of space, unless your project rate bottom left of Audacity is way below the recommended 44100 Hz.
I would guess these tracks are imported WAV or AIFF files and you have chosen not to copy them into the project. This saves space but only until you edit the audio. See Import / Export Preferences.
I think Stereo Track to Mono would copy in the data if you had not already done so, which would make the project larger.
Also remember that Audacity has Undo and Redo ability which needs disk space. Every new action adds to disk space usage until you close the project or use View > History… to remove Undo steps.
When you close the project all Undo/Redo steps are removed and the data used is solely that for the visible project as you saved it.
Gale
Hi,
-no dependencies (pretty sure about that)
…ie I think all the date the project needs is in the data folder.
I always like to have all the wav data in the project data folder, so I always
use the “safest” way when opening a project, the “make a copy” way
…also the “when saving project that depends on other audio files” I have
“ask user” and it never asks, indicating no dependencies I think.
-project closed, so no undo history
Do the tracks have the same sample rate and sample format?"
yes, all 16 bit, 44100Hz
-project rate 44100hz
By default that should take about 1.4 GB of space
-perhaps generally smaller project data folder overall in my case because parts of some tracks are empty,
ie I recorded parts of some tracks for only a few bars at perhaps 5 minutes into the piece
I think Stereo Track to Mono would copy in the data if you had not already done so, which would make the project larger
quite sure I had already done so as noted above I think, if I’m understanding this correctly
So lets say one has a project with 8 stereo tracks with no dependencies, and then closes the project.
Are we saying that if nothing else is changed at all except all tracks have been made stereo to mono,
then close the project, that the mono tracks project data folder should be around half the size?
I thought they might be around half the data size.
Thanks for any more ideas.
frew
Empty space in a track has no data (size zero).
When empty space is rendered as silence, samples with zero amplitude are generated in place of the empty space.
“Silence” (zero amplitude samples) has the same amount of data as any other audio (by default, 44100 samples per second per channel with 4 bytes per sample).
(There is a special case when generating silence, in that Audacity will use a kind of place-holder rather than sample data to represent silence - in this special case the silence is zero bytes.)
So you have changed Audacity’s default settings to lower quality? Why did you do that?
Yes I believe so, assuming the audio in each track is different.
Gale
edit: all along I’ve had Preferences> Quality> Default sample (edit: format) 16 bit, because I thought it would
be easier on my older system, and that it would sound well enough, less dropouts in recording with lower latencies
during recording, and that it might take less room on hard drive in data folders…
Empty space in a track has no data (size zero).
When empty space is rendered as silence, samples with zero amplitude are generated in place of the empty space.
“Silence” (zero amplitude samples) has the same amount of data as any other audio (by default, 44100 samples per second per channel with 4 bytes per sample).
…sorry, not following exactly…no rendering taking place yet, just saving the project
assuming the audio in each track is different
sorry, not sure what that’s referring to
So I have a situation where I like to sometimes make all my tracks stereo to mono,
even though I initially record them stereo.
I took a few projects that had stereo tracks, opened them, and only did a stereo to mono for each track,
then saved the projects with new names, closed the projects, and checked their data folder sizes.
I was surprised to see the data folders of the mono track folders were over three times as big
as the original stereo track projects.
Oh well, not a major problem…just wondering why the data folders got bigger rather than smaller after
only making the tracks stereo to mono.
Thanks,
frew
I thought you were doing: “Tracks menu > Stereo Track to Mono”.
If so, then that “mixes” the two channels of the stereo track to render a new mono track. Any empty space between audio clips will be rendered as silence.
Example:
Stereo track:
After converting (mixing) to mono:
I thought you were doing: “Tracks menu > Stereo Track to Mono”.
If so, then that “mixes” the two channels of the stereo track to render a new mono track. Any empty space between audio clips will be rendered as silence.
Ah yes, I see now.
Many of my stereo tracks had lots of empty spaces before and after audio clips.
So apparently when a project is saved in what I’m calling it’s original stereo track state,
with all the empty spaces before and after audio clips, Audacity is not using hard drive
space to store those spaces.
When the stereo tracks are changed to mono, something happens where Audacity now has to
deal with those spaces by giving them actual .au files, thus accounting for the larger data folder
sizes in situations where stereo tracks with spaces in them have been actually “rendered” to mono.
(or something like that)
Just a fine point, but it may be nice to have a little info about this in the help file, or perhaps
Tracks> Render Stereo Track to mono (with perhaps info that pops up mentioning it will increase
project size if Stereo Tracks contain empty spaces before and and/or after audio clips).
You’ve really helped a lot and I really appreciate it.
Thanks again,
frew
Well, I just deleted all the stereo tracks that had spaces, and was left with three stereo tracks, with no spaces,
around 7min long each track, and the data folder is 47MB.
After all three tracks stereo to mono, data folder 208 MB.
So I have another theory, perhaps so simple we overlooked it because I did not give thorough information.
Each of my three stereo tracks consists of not one continuous recording, but rather 30 second recordings
copied and pasted numerous times to make up a 7 min tracks. So audacity is probably just reusing those
clips, not having separate data for each clip…as long as the tracks remain stereo, as originally recorded.
But when rendered to mono by Track> Stereo track to mono, the whole track now has to be turned into
those au files, thus accounting for the very much larger data folder size.
This is probably what accounts for the majority of the data file size increase, along with what you’ve presented
in your images of any empty space between audio clips will be rendered as silence.
Sorry I did not mention from the beginning that my stereo tracks had multiple repetitions of audio clips.
Does this sound like what may be happening to partially account for the larger data folder sizes when I
turn all my stereo tracks into mono tracks?
Thanks,
frew
Yes, Audacity will reuse the data from the original clip until the clip or copy is modified.
For example, if you record 5 seconds, mono, 32-bit float, 44100 Hz, that will produce one blockfile of about 1 MB.
If you repeat that 5 second clip 9 times, either by copy and pasting or with the “Repeat” effect, the project data will still contain one blockfile of about 1 MB.
If you then amplify (any) one of the 5 second clips, the project data will then contain two blockfiles of about 1 MB each (the original one and a new one for the amplified clip).
Excellent, thanks so much.
frew
@frew_few: Please use the Quote button in the message composition window to quote what someone said, or make the quotes more obvious such as
Steve wrote: We need more information
Otherwise the posts can get very confusing.
Gale
Just to add, a really easy way to quote a previous post:
The forum software will then copy the selected text into your new post, and place “quote tags” around it that look like this:
[quote="Gale Andrews"]@frew_few: Please use the Quote button in the message composition window to quote what someone said,[/quote]
I can’t actually get that to work here unless I use the “Quote” button and select the text to be quoted in the message editing window.
If I use the “Post Reply” button the message editing window has no text, and selected text outside that window is not included inside the Quote tags.
Gale
Are you clicking the right “QUOTE” button?
There’s a “Quote” button in the row of buttons above the message compose box. That just adds (empty) quote tags.
There’s also a “QUOTE” (upper case) button in the top right corner of each previous post - that’s the one that I’m referring to. In this post I selected your text in your post, then clicked the “QUOTE” button at the top right of your post.
I was thinking of Audacity reusing audio data that is the same, as discussed recently, so that if you had one track then copy/pasted that to new tracks (or duplicated) to make eight tracks, this takes no more disk space than one track.
If for example you have two stereo tracks using identical data in all four channels that only requires two block files, selecting both stereo tracks and using Stereo Track to Mono, leaving two mono tracks, does in fact double space usage to four block files after closing the project.
And if for example one stereo track with unique data and no empty space takes four block files, Stereo Track to Mono will halve space usage to two block files after closing the project.
These effects on space usage are because Stereo Track to Mono renders the data.
It is certainly a complex subject.
Gale
Yes that is the QUOTE button I mean that makes it work (if I select the text in the message editing window then press the “Quote” button above the message window).
But you said
I assumed by that you meant “POST REPLY” (bottom left) which doesn’t work (because there is no text in the message editing window).
Gale
Yes, I see what you mean. Thanks for the heads up about that.
Okay, thanks. Checking that technique now.
I see that you’re referring to the “POSTREPLY” button at the bottom of the thread page.
And by the scrolling you refer to the scrollable TOPIC REVIEW area below the POST A REPLY area.
Very nice.
Thanks again to you both for your kind and thorough help with this great program.
frew
I see what you were referring to, now that I see how Audacity reuses clips that have
not been rendered in any way in tracks.
It’s nice that Audacity saves hard drive space when a clip is copied and pasted.
Thanks for going over that.
frew